Congestive heart failure is a major cause of death in United States despite attempts to decrease mortality by drugs. Minimizing stress on the heart has been shown to be more effective in controlling congestive heart failure than using drugs that stimulate the heart. Flosequinan, a vasodilator (an agent that has improved congestive heart failure mortality rates) acts by dilating blood vessels without significantly stimulating the heart. This study is designed to evaluate the role of flosequinan in C H F.